1. Field of the Invention
The present invention is related to a parking guidance system, and more particularly to a back-up sensor system installable on large vehicles and operated by wireless signal transmission.
2. Description of Related Art
Back-up sensors are becoming standard equipment in small passenger vehicles. Currently, dual-sensor versions and four-sensor versions are available on the market. In fact, small passenger vehicles only need a pair of back-up sensors on the rear bumper for obstacle detection when they are moving in the reverse direction.
However, current designs of back-up sensors make no distinction between passenger cars and large vehicles. Large vehicles such as trucks, trailers, buses and articulated vehicles require more than one pair of sensors around the sides and the back of the vehicles. Since their extended chassis and enormous bodies often block off a large portion of the driver's view especially around the rear section of such vehicles, additional sensors are required to cover the blind spots.
The conventional back-up sensors are hard-wired to a control box that is connected to a console unit in the driver compartment. For a large vehicle, the rear bumper is usually very far from the driver compartment. Therefore extensive wiring is needed to connect multiple back-up sensors on the vehicle bumper to the control box in the driver compartment. Also, this type of installation often involves drilling many holes in the external shell through which electrical wires pass to the driver's compartment.
Since back-up sensors are conventionally installed on the vehicle's rear bumper with external wiring, the sensors and the wiring are subject to wear and tear from nature and abrasive wear.
Therefore, conventional back-up sensor installations on large vehicles faced system reliability and complicated installation problems.